Backrest for a bench



FIG. 1 is an upper perspective view of the backrest for a bench showing my new design.

FIG. 2 is a front view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a side view thereof;

FIG. 5 is an opposite side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The features presented in broken lines are for environmental purposes only and form no part of the claimed design. 

CLAIM The ornamental design for a backrest for a bench, as shown and described. 